title: Investigation of peptide splicing using two-peptide-chain analogs of trypsin inhibitor SFTI-1.
abstract: This study examines peptide splicing catalyzed by serine proteinases. A series of two-peptide-chain analogs of trypsin inhibitor SFTI-1 were designed and synthesized via the solid-phase method. All consisted of two peptide chains (also called N- and C-terminal fragments) joined together by one disulfide bridge. The analogs were incubated with bovine β-trypsin or bovine α-chymotrypsin. Analysis of MS data analysis showed that, after enzyme-catalyzed degradation of the single peptide bond between the Lys and Ser residues located at the C-terminus of the C-terminal peptide chain, a new peptide bond was formed. This bond brought together the separated peptide chains, and, as a result, monocyclic SFTI-1 was recovered. This proteolytic route of peptide rearrangement appears to be similar to peptide splicing catalyzed by proteasomes. However, the proteasome is much more complex than 'classical' serine proteinases.
authors.affiliation: Department of Bioorganic Chemistry, Faculty of Chemistry, University of Gdańsk, Poland.
authors.forename: Natalia
authors.initials: N
authors.lastname: Karna
authors.forename: Dawid
authors.initials: D
authors.lastname: Dębowski
authors.forename: Agata
authors.initials: A
authors.lastname: Gitlin
authors.forename: Anna
authors.initials: A
authors.lastname: Łęgowska
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Rolka
mesh_terms: D000818:Animals; D002417:Cattle; D002918:Chymotrypsin / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010447:Peptide Hydrolases / Q000378:metabolism; D010456:Peptides, Cyclic / Q000138:chemical synthesis / Q000494:pharmacology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014357:Trypsin / Q000737:chemistry* / Q000378:metabolism; D014361:Trypsin Inhibitors / Q000494:pharmacology*
chemical_list: D010456:Peptides, Cyclic; C448501:SFTI-1 peptide, sunflower; D014361:Trypsin Inhibitors; D010447:Peptide Hydrolases; D002918:Chymotrypsin; C117608:alpha-chymotrypsin; D014357:Trypsin
keywords: SFTI-1; inhibitors; intermolecular disulfide bridge; peptide splicing; serine proteinases